The present invention relates to vacuum valves and, more particularly, to filter systems coupled with a vacuum valve to protect the vacuum system against an overflow of molten material.
In the vacuum die casting industry, it is desirable to remove air and other gases from the die cavity prior to injection of a molten metal shot which results in improved flow of the molten material into the die cavity which, in turn, produces a casting having improved grain structure and surface finish. Evacuation of the die cavity is generally accomplished by a venting device that is in fluid communication with the die cavity. Also, various types of filter devices may be in the vacuum path to remove contaminants and to prohibit overflow of the molten material.
Accordingly, the present invention is directed to an improved filter system for a vacuum valve for use in a vacuum die casting apparatus which may be directly mounted to or integrated into the casting dies or die blocks between the die cavity and a vacuum source.
It is an object of the present invention to provide a filter system which adequately filters the air and gases exiting the die cavity as well as provide a serpentine flow path through the filter system. The filter system is also compressible so that if overflow of molten material occurs, the filter system will collapse, prohibiting the molten material from entering into the vacuum source.
Further, the filter system enables removability of the system from the die casting or disconnection of an auxiliary filter system for easy and rapid cleaning of the filter element. Also, the filter systems are easily replaceable.
From the following detailed description taken in conjunction with the accompanying drawings and subjoined claims, other objects and advantages of the present invention will become apparent to those skilled in the art.